103 



The next areas of Cambrian Serpentines are those which occur in 

 Eastern Canada, or more generally known as the Eastern Townships 

 serpentines. They are by far the most important ones of the whole 

 Dominion, not only on account of affording rich minerals, but also as 

 being considered by some as an altered metamorphic rock contempo- 

 raneous in age with those highly metamorphosed strata which constitute 

 the Quebec group. 



Ever since the establishment of the Geological Survey, work has 

 been done almost every year in that part of the Province of Quebec 

 called the Eastern Townships, and very highly interesting facts have 

 been collected by the different gentlemen of the Geological staff who 

 were given this section of the country to work out ; but it is not until 

 1886 that the first geological map of a part of that sectiorr of our terri- 

 tory was published to accompany Dr. Ells's report of that same yew. 

 Though no map had previously been published, much had been said of 

 the complicated set of rocks of that region, not omitting the famous 

 serpentines which very often form vast masses almost without admix- 

 ture, and at other times, enclose diallage, actinolite, garnet, and chromic 

 iron, or are intermingled with carbonate of lime, dolomite and some- 

 times with ferruginous magnesite, forming varieties of ophiolite rock 

 into which talc often enters. They almost always contain small por- 

 tions of chrome and nickel while these two metals appear to be 

 altogether wanting in the similar rocks of the Laurentian series. 



These serpentines which are closely allied to a band of diorite and 

 dioritic rocks, extend from the Township of Potton, on the west side of 

 Lake Memphremagog, and a few miles only north of the International 

 Boundary line, in a north-eastward direction across the St. Francis 

 River, or a stretch of about 115 miles. They appear in irregular but 

 generally well defined masses and bosses, and although showing only 

 here and there, the most of that distance, th«y do not deviate from the 

 aforesaid direction except in the Townships of Shepton and Cleveland 

 where they were around eastward towards the Township of Ham, 

 whence they follow the general trend of all the formation, which is north} 

 east. Sir Wm. Logan and Dr. T. S terry Hunt held these serpentines 

 to be of sedimentary origin, but Dr. Selwyn in the Geological Survey 

 report of 1877-78, says : — 



